1. Field of Invention
The present invention relates to the technical field of electronic devices, specifically to a winding and a method for preparing a winding applied to an inductive device.
2. Description of Related Arts
An inductor or a transformer is a common device in an electronic circuit, and the inductor and the transformer both comprise a winding of electrical wire. Along with development of the integrated circuit technology, the inductive devices are generally prepared by adopting one conductive layer or a plurality of conductive layers. Because a winding using one conductive layer ordinarily occupies a large chip area, a winding using the plurality of conductive layers can be applied in designing an inductive device. However, inductive devices based on a winding using the plurality of conductive layers reveal some critical shortcomings with regards to the self-resonance frequency and the Q-factor.
For example, in a China patent application No. 99110933.3, an inductor device and a preparation method thereof are provided, where in the inductor device, each layer of conductive unit is U-shaped, and two adjacent layers of U-shaped loops are disposed oppositely, so as to form a conductive loop spatially through connection.
Moreover, many US patents such as U.S. Pat. Nos. 6,380,835, 6,870,457, 6,967,555, 7,091,814, No. 2011/0133878, U.S. Pat. Nos. 8,325,001, 8,258,192, 7,253,712, No. 2013/0026846, U.S. Pat. No. 8,198,970, No. 2012/0274434, U.S. Pat. Nos. 7,986,210, and 7,768,372 respectively disclose various structures of symmetrical stacked inductors or transformers.
In view of the above, the various symmetrical stacked inductor or transformer winding includes a plurality of conductive loops or conductive half-loops forming a symmetrical and geometrical shape in a single conductive layer or multi layers. In the multi-layer structure, each layer generally includes at least one loop or one half loop. Generally, the plurality of loops is electrically connected by adopting crossover bridges.
However, no matter in the single layer structure or in the multi-layer structure, the geometric centers of loops are spatially coincident and the adjacent loop lines overlap, thereby may affecting the performance of the inductor and transformer such as the self-resonance frequency and the Q-factor.